Dancing Tutorial - Dancer

Dancing Tutorial Alberto Manuel Brand˜ao Sim˜oes [email protected]

Braga Geek Nights March 1st

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Part 0: Ballet

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What’s Dancer?

A micro framework for writing web applications

So, Yet Another Web Framework?

Well, yes!

CGI.pm webapps are spaghetti

Catalyst is HUGE

Ruby introduced something different

We needed something similar in Perl

Definitely

And they also imitated us!

Available at http://perldancer.org and in GitHub.

Part 1: Tango

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Installing

 

 $ sudo cpan Dancer



or

 

 $ sudo cpan Task : : Dancer



or yet

 



$ cpanm −S Task : : Dancer

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Bootstrap application 



 $ + + + + + + + + + + + + + + + + + +

dancer −a MyApp MyApp / bin / app . pl MyApp / config . yml MyApp / environments / development . yml MyApp / environments / production . yml MyApp / views / index . tt MyApp / views / layouts / main . tt MyApp / lib / MyApp . pm MyApp / public / javascripts / jquery . js MyApp / public / css / style . css MyApp / public / css / error . css MyApp / public / images / . . . MyApp / public / 5 0 0 . html MyApp / public / 4 0 4 . html MyApp / public / dispatch . fcgi MyApp / public / dispatch . cgi MyApp / Makefile . PL MyApp /t /002 _index_route . t MyApp /t /001 _base . t Alberto Sim˜ oes

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What’s inside  

 + MyApp / bin / app . pl



a standalone light server (starts server in port 3000); also used for fast-cgi or common cgi backends; 



 + MyApp / config . yml + MyApp / environments / development . yml + MyApp / environments / production . yml

main configuration file (plugins, modules, etc); configuration files for production and development: defines what to report, where to report, etc.

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What’s inside  

 + MyApp / bin / app . pl



a standalone light server (starts server in port 3000); also used for fast-cgi or common cgi backends; 



 + MyApp / config . yml + MyApp / environments / development . yml + MyApp / environments / production . yml

main configuration file (plugins, modules, etc); configuration files for production and development: defines what to report, where to report, etc.

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What’s inside  

 + MyApp / views / index . tt + MyApp / views / layouts / main . tt



Templates and layouts: templates are page portions/scraps; layouts are full page designs (they are automagically filled by the template); 



 + + + +

MyApp / public / javascripts / jquery . js MyApp / public / css / style . css MyApp / public / css / error . css MyApp / public / images / . . .

public/static files: javascript (Dancer ships with jsquery); cascade style sheets; images (for default design); Alberto Sim˜ oes

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What’s inside  

 + MyApp / views / index . tt + MyApp / views / layouts / main . tt



Templates and layouts: templates are page portions/scraps; layouts are full page designs (they are automagically filled by the template); 



 + + + +

MyApp / public / javascripts / jquery . js MyApp / public / css / style . css MyApp / public / css / error . css MyApp / public / images / . . .

public/static files: javascript (Dancer ships with jsquery); cascade style sheets; images (for default design); Alberto Sim˜ oes

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What’s inside  

 + MyApp / public / 5 0 0 . html + MyApp / public / 4 0 4 . html



pages for 500 and 404 errors;  

 + MyApp / public / dispatch . fcgi + MyApp / public / dispatch . cgi

wrappers to configure fast-cgi and cgi backends; will be back on this later (future talk?);

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What’s inside  

 + MyApp / public / 5 0 0 . html + MyApp / public / 4 0 4 . html



pages for 500 and 404 errors;  

 + MyApp / public / dispatch . fcgi + MyApp / public / dispatch . cgi

wrappers to configure fast-cgi and cgi backends; will be back on this later (future talk?);

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What’s inside 



 + MyApp / Makefile . PL + MyApp /t /002 _index_route . t + MyApp /t /001 _base . t



Main module Makefile: usefull to make module of your application

Your test suite;  

 + MyApp / lib / MyApp . pm



Your application!

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What’s inside 



 + MyApp / Makefile . PL + MyApp /t /002 _index_route . t + MyApp /t /001 _base . t



Main module Makefile: usefull to make module of your application

Your test suite;  

 + MyApp / lib / MyApp . pm



Your application!

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Part 2: Flamenco

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Traffic Control

Your MyApp/lib/MyApp.pm includes:





p a c k a g e MyApp ; u s e Dancer ’ : s y n t a x ’ ; our $VERSION = ’ 0 . 1 ’ ; get ’ / ’ => sub { template ’ i n d e x ’ ; }; true ;





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How to test it? Start the standalone server,





[ ambs@rachmaninoff MyApp ] $ bin / app . pl



that shows debug info,







[ 9 3 8 7 ] core @0 .000017 > loading Dancer : : Handler : : Standalone handler in / opt / lib / perl5 / site_perl / 5 . 1 2 . 3 / Dancer / Handler . pm l . 39 [ 9 3 8 7 ] core @0 .000442 > loading handler ’ Dancer : : Handler : : Standalone ’ in / opt / l o c a l / lib / perl5 / site_perl / 5 . 1 2 . 3 / Dancer . pm l . 230 >> Dancer 1 . 3 0 1 1 server 9387 listening on http : / / 0 . 0 . 0 . 0 : 3 0 0 0 \ subsection { Entering the development dance floor . . . }



and open a browser in the specified port.

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It Works!

Route Handlers

A Dancer app is a collection of route handlers; A route handler is, basically, a sub; It is bound to an http method; And to a path or a path pattern; Example get ’ / ’ => sub { . . .

};

post ’ / s u b m i t / : f i l e ’ => sub { . . . del ’ / r e s o u r c e /∗ ’ => sub { . . .

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};

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};

Route Handlers

A Dancer app is a collection of route handlers; A route handler is, basically, a sub; It is bound to an http method; And to a path or a path pattern; Example get ’ / ’ => sub { . . .

};

post ’ / s u b m i t / : f i l e ’ => sub { . . . del ’ / r e s o u r c e /∗ ’ => sub { . . .

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};

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};

Route Handlers Static patterns (paths):



get ’ / ’ => sub { . . .



 };

get ’ / a b o u t ’ => sub { . . .

};

Patterns with named tokens:



 

get ’ / book / : i d ’ => sub { # do s o m e t h i n g w i t h params −>{i d } ... };



get ’ / u s e r / : g r o u p / : u i d ’ => sub { # u s e params −>{u i d } and params −>{g r o u p } h e r e };

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Route Handlers Static patterns (paths):



get ’ / ’ => sub { . . .



 };

get ’ / a b o u t ’ => sub { . . .

};

Patterns with named tokens:



 

get ’ / book / : i d ’ => sub { # do s o m e t h i n g w i t h params −>{i d } ... };



get ’ / u s e r / : g r o u p / : u i d ’ => sub { # u s e params −>{u i d } and params −>{g r o u p } h e r e };

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Route Handlers Patterns with anonymous tokens:





get ’ / f i l e / ∗ . ∗ ’ => sub { my ( $file , $ext ) = splat ; ... }



get ’ / show /∗/∗ ’ => sub { my ( $cat , $subcat ) = splat ; };

Regular expressions:







get qr { post / ( \ d+)−(\d+)−(\d+)} => sub { my ( $year , $month , $day ) = splat ; }

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Route Handlers Patterns with anonymous tokens:





get ’ / f i l e / ∗ . ∗ ’ => sub { my ( $file , $ext ) = splat ; ... }



get ’ / show /∗/∗ ’ => sub { my ( $cat , $subcat ) = splat ; };

Regular expressions:







get qr { post / ( \ d+)−(\d+)−(\d+)} => sub { my ( $year , $month , $day ) = splat ; }

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Part 3: Mambo

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Templating

Dancer has plugins for most templating systems: Mason, Template Toolkit and others. Default is a Simple template system, built-in Dancer. Use the template inside the route:







get ’ / u s e r / : name ’ => sub { template ’ p r o f i l e ’ => { username => params−>{name } } ; };



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Templating

Dancer has plugins for most templating systems: Mason, Template Toolkit and others. Default is a Simple template system, built-in Dancer. Use the template inside the route:







get ’ / u s e r / : name ’ => sub { template ’ p r o f i l e ’ => { username => params−>{name } } ; };



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Rerouting

You can reroute by: Passing the control to the next matching handler:





get ’ / l a z y ’ => sub { pass and r e t u r n false ; };



Redirecting to other URI:







get ’ / f o r b i d d e n ’ => sub { r e t u r n redirect ’ / b e t t e r / p l a c e ’ };

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Rerouting

You can reroute by: Passing the control to the next matching handler:





get ’ / l a z y ’ => sub { pass and r e t u r n false ; };



Redirecting to other URI:







get ’ / f o r b i d d e n ’ => sub { r e t u r n redirect ’ / b e t t e r / p l a c e ’ };

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Rerouting

You can reroute by: Passing the control to the next matching handler:





get ’ / l a z y ’ => sub { pass and r e t u r n false ; };



Redirecting to other URI:







get ’ / f o r b i d d e n ’ => sub { r e t u r n redirect ’ / b e t t e r / p l a c e ’ };

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Serving Files You can serve a static file:





get ’ / dowload / : f i l e ’ => sub { my $file = params−>{file } ; pass and r e t u r n false u n l e s s −f $file ; send_file $file ;



};



If the content is generated, just change content-type:





get ’ / readme . t x t ’ => sub { content_type ’ t e x t / p l a i n ’ ; return ’ this is plain text ’ };

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Serving Files You can serve a static file:





get ’ / dowload / : f i l e ’ => sub { my $file = params−>{file } ; pass and r e t u r n false u n l e s s −f $file ; send_file $file ;



};



If the content is generated, just change content-type:





get ’ / readme . t x t ’ => sub { content_type ’ t e x t / p l a i n ’ ; return ’ this is plain text ’ };

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Thanks to Alexis Sukrieh (I stole some slides)